鈍感
どんかん · donkan · JLPT N1 · na-adj
thickheadedness
🪨 鈍 = dull, blunt + 感 = sense: a blunted sense, so hints slide right past you
鈍 means dull or blunt, like a blade that won't cut. Joined with 感 (sense), it describes senses that are dulled, so you miss subtle cues and stay unmoved.
感 — heart 心 + 咸 (xián, phonetic)
A semantic-phonetic compound. The heart radical 心 at the bottom carries the meaning of feeling or emotion, while 咸 supplies the sound. Together 感 conveys being moved in the heart, hence 'to feel,' 'sense,' or 'be affected by' something.